Active Warning Devices

Flashing Lights With Gates and Signal Preemption Projects

The determination of the need and selection of devices at a grade crossing is made by public agencies with jurisdictional authority. Subject to such determination and selection, the design installation and operation shall be in accordance with all applicable Federal and State standards and regulations, and local policies, laws and ordinances. Compliance with State regulations also ensures that the highway agency or other governmental agency responsible for making system and equipment determinations selects appropriate vehicular traffic control signs and/or devices for specific public highway intersections. Union Pacific will contribute information to assist agencies with their decision.

At some intersections, it may be necessary to coordinate the traffic signals with highway-rail grade crossing warning devices. The highway agency will determine if preemption is required and the appropriate timing for the traffic signals and highway-rail grade crossing warning devices. Preemption of the cycle of traffic signals at highway intersections near highway-rail grade crossings requires careful review by highway traffic engineers to determine the appropriate timing and sequence for both the traffic signal and the highway–rail grade crossing warning system. Preemption for the traffic signal may be simultaneous with, or in advance of the warning system activation.

The Industry and Public Project Group will review all projects proposing alterations to highway-rail grade crossings and/or warning systems. Included will be all projects which involve the installation of new warning systems, removing and/or relocating existing systems and modifying/upgrading existing systems, and coordination of traffic signals with warning system.

The Agency should contact the appropriate Manager of Industry and Public Projects and forward a Preliminary Engineering Agreement along with a concept print. If the project includes Traffic Signal Preemption, a copy of the study used to determine if the preemption is simultaneous or advanced is required.